As record heat baked Baltimore, a wave of violence unfurled across the city: six shootings and eight people wounded over a period of less than eight hours.
The first shots were fired around dinnertime Wednesday, and the violence continued until after 2 a.m. Thursday. Police have no suspects in any of the crimes — which included two double shootings — and believe the seven wounded men and one injured woman will survive.
Several academic studies of crime suggest that it's no coincidence that the outburst of violence came as the temperature at the Inner Harbor hit 96 degrees. Researchers have debated the subject for years, but those who see a link say warmer weather drives people from their homes and into potential conflicts.
"One of the things in Baltimore is there's not a lot of air conditioning, so people move outside," said Phil Leaf, associate director of the Johns Hopkins Urban Health Institute. "The more you have different people interacting, the more chance you have for beefs."
Baltimore police say they don't need statistics to tell them what they already know from patrolling the same city streets as winter turns to spring and summer.
"We can all look at seasons of the moon and we can look at the weather," police spokesman Anthony Guglielmi said. "But if you ask a cop what their gut feelings are, yeah, things get crazy when it gets hot outside.
"What we do know is when the weather's warm, people go outside."
The National Weather Service reported a high temperature of 91 degrees at BWI-Marshall Airport on Wednesday, which broke a 91-year record. And a reading at the Inner Harbor hit 96 degrees, which tied Port Isabel, Texas, for the highest temperature in the United States on Wednesday.
It was one of the most violent nights recorded in the city so far this year.
Police are not overreacting to Wednesday night's shootings, Guglielmi said, but are working to "drill down" into each incident, looking for connections to gangs and drugs and developing sources that help police get in front of any retribution.
But the warm weather does mean police are shifting strategies. That includes shuffling schedules for patrol and plainclothes officers and even permitting officers to wear short-sleeve uniform shirts — an annual changeover that started Monday.
On the streets where the wounded were hauled away in ambulances overnight, people speculated Thursday on the causes of the violence.
"I don't know," said Meechie Thornton, 53, just half a block up from the intersection of West Fayette and North Stricker streets where a man was shot in the left side while sitting in a car. "They just go buck wild."
Thornton sat on the step of a brick rowhouse on Fayette Street talking to Kenyatta Player, 34, who wore a summer dress and sunglasses in the warm breeze.
"When it gets hot, people are crazy," Player said. As she spoke, a car screeched up the street.
"See? That made no sense whatsoever."
Researchers have tried to make some sense of the connection between heat and violence.
Psychologists at Florida International University looked at crime reports in Minneapolis for a 2000 study and found crime was more prevalent during the summer than in other seasons.
Similarly, a 2010 study conducted through Kent State University found that violent crime in Cleveland increased as temperatures rose.
Craig Anderson, who directs the Iowa State University's Center for the Study of Violence, has also studied the relationship between temperature and crime. He said heat tends to make people cranky, which can amplify minor provocations.